It is typical of motor vehicles to have a front door opening and an optional rear door opening that are respectively closable with separate front and/or rear doors. Most vehicles on our roads are equipped with conventional doors that are either hinged at the front-facing edge of the door or (in some instances) on the rear-facing edge, thus allowing the door to swing outward horizontally from the body of the car. Other configurations include gull-wing doors and scissor doors that rotate upward.
Gull-wing doors are doors that are hinged at the roof of the vehicle and thus open out and up. Scissor doors are typically hinged on the front pillar of the vehicle and also open in upward motion. On both gull-wing and scissor doors, the opening process is typically supported by pressurized cylinders so that the door does not close under its own weight.
Examples of automobiles with gull-wing doors including the 1950s Mercedes Benz 300SL and the 1980s DeLorean DMC-12. More recently, the Mercedes Benz SLS AMG and the Tesla Model X have also incorporated gullwing doors.
The door design of the Mercedes Benz SL provided an unusual chassis design that necessitated a very high door sill and required that the doors be smaller than would otherwise have been optimal. The door design of the DeLorean attempted to solve these problems by using a solid steel torsion bar to counterbalance a full size door and pneumatic struts to open the doors dampen movement of the doors.
A typical gull-wing door has a one piece configuration that is hinged at the roof, as described, for example, in U.S. Pat. No. 4,378,658 to DeLorean, the subject matter of which is herein incorporated by reference in its entirety. The use of articulated gull-wing doors has also been suggested and examples of articulated gull-wing doors can be found, for example, in U.S. Pat. No. 5,992,918 to Hoffman, and in U.S. Pat. No. 8,449,015 to Brown et al., the subject matter of each of which is herein incorporated by reference in its entirety. In addition, DE 10200502133A1 to Volkswagen describes a vehicle door, including a gull-wing door, that is of a telescopic form and in which the lower region of the door is able to slide over the upper part of the door.
An advantage of gull-wing doors is that when properly designed, they allow much better entrance/egress than conventional doors, thus more easily facilitating access for passengers as well as storage of wheelchairs and cargo. However, these doors typically require more vertical clearance when the door is in a fully open position. Thus, it is would be desirable to minimize the distance by which the door extends above the vehicle body, thus limiting interference with a garage ceiling or other potential obstruction. It would also be desirable to limit the horizontal side clearance needed to open the door.
While various gull-wing door configurations have been suggested, further improvements to gull-wing door configurations are also be desirable, including minimizing still further the side clearance necessary to open the door while at the same time also minimizing the distance by which the door extends above the vehicle body when in a fully open position.
In addition, it would also be desirable to provide an improved gull-wing door kit, including components and assemblies, which would allow automotive manufacturers and aftermarket enthusiasts the ability to incorporate gullwing door operating in currently designed automobiles, without any modification to the automobile body.